Could you show us what exactly is giving you trouble? What do you get when you attempt them?
For this we need to use the quotient rule which is:
In your case and
I will differentiate the numerator as that's what seems to be the issue then you can try using my value of in the quotient rule. FYI my final answer is
To find u' (du/dx) we need to work out .
For simplicity and clarity's sake let . From the chain rule we know that
Due to this substitution we can rewrite u as .
Differentiating this function is easy:
Similarly 1/x is also easy to differentiate:
From the chain rule above:
Since we get in terms of x:
Therefore